This thesis considers the effect of corporate provision of social welfare on the legitimacy of the state. This research consists of a literature review, quantitative and qualitative research. The following research questions are addressed 1. What is the relationship between social welfare provision and the legitimacy of a) the state and b) the corporation? 2. What are the consequences when some of these social welfare responsibilities are assumed by corporations in terms of a) The legitimacy of the corporation and b) The legitimacy of the state – i.e. have corporations adopted some of the legitimacy of the state along with the functions of the state? The questions were addressed with case study research conducted in South Africa, in to the provision of anti-retroviral drugs to HIV positive employees by their employers. This case study was chosen because South Africa, a newly democratic country was facing a significant challenge in HIV to which the state did not initially respond well. Many large companies, and the mining industry in particular, have been involved in providing treatment to employees, their families and to the wider community since the early stages of the crisis. Therefore the South African context offers a clear example of where corporations have assumed some of the social welfare responsibilities of the state. The first research stage consisted of quantitative analysis of public and private investment in health, corporate social investment spending and attitudes to the government and to major corporations over a sixteen year period. The second research stage consisted of interviews and a focus group with people receiving anti-retroviral treatment from their employers, those involved in the provision of the treatment, representatives of the broader South African community and academic experts. The findings from both stages were considered together in order to gain an understanding of the relationship between the involvement of corporations in providing healthcare and attitudes to the legitimacy of the state. These questions were addressed by appealing to the social contract, both as it is used in traditional political philosophy and how it has been applied more recently to business ethics. The research questions were based on an implicit assumption that there was a direct, and probably negative relationship between the corporate provision of social welfare and the legitimacy of the state because it was assumed that the state and the corporation would be competing for legitimacy in a zero sum game. The findings of the research suggest a more complex relationship, where corporations are seen to fulfil some terms of the social contract on the behalf are the state. This means that rather than usurping the legitimacy of the state, corporations may actually be bolstering the legitimacy of the state. Therefore the risk initially identified, that the provision of ARVs by employers will de-legitimise the state, was not realised. The findings were much more positive, with significant implications. Specifically, if corporations have the power to lend legitimacy to states they may also have a responsibility to ensure that this power is used wisely, and further consideration is required of the conditions under which such legitimation is appropriate.